The present invention relates generally to an apparatus and method for separating and extracting liquids from a mixed composition, and more specifically, an apparatus and method for use in separating a mixed composition of waste water, sludge, and oil for the removal of the waste water.
A conventional vehicle wash station will generate large quantities of dirty water which includes a small percentage of oil washed from or leaking from various trucks using such a vehicle wash. Most facilities will include an on-site separator which separates out much of the water, with the oil, sludge, and some water remaining in a sump. Periodically, a simple vacuum truck has been used to remove all of the oil, water, and sludge from the sump of the on-site separator system, and to transport the mixed composition to a central disposal site. Such a method is costly and wasteful in that the cost of such a service is based on the gallons of mixed composition that is transported. The water in such a mixed composition could be left at the truck stop, so the customer pays a great deal for transporting what is mostly water that could have been left behind.
Various designs have attempted to provide a design that removes water from grease in an efficient manner. Such a design is shown in U.S. Pat. No. 5,637,233 to Earrusso. The Earrusso patent addresses the problem of disposing of a grease/water mixed composition such as that found at restaurants. The portable separator tank has a complex system using multiple compartments to separate water from grease. The water and grease are pumped into a first compartment and separated according to their densities, the grease typically floating above the water. A tube opening is located near the bottom of the tank to drain the water that is near the bottom of the first compartment into a second compartment. The tube opening can then be closed when the grease begins to be drained through the tube. Although the tube avoids suctioning the grease due to the tube's position at the bottom of the tank and the position of the grease above the water, this design fails to protect the suctioning pipe from drawing other materials located at the bottom of the first compartment that are more dense than water, such as sludge.
What is needed, then, and not found in the prior art, is an apparatus for separating water from a mixed composition of oil, water, and sludge and removing the water while leaving the oil and sludge for remote disposal.